Water table facts for kids

The water table is like an invisible line underground. It's the level where the soil and rocks are completely filled with water. Think of it as the top surface of all the water hidden beneath the ground. If you dig a well, the water table is where you'll find water.

This underground water is called groundwater. It comes from rain and snow that soaks into the ground, or from water flowing into underground storage areas called aquifers. The water table isn't always at the same depth; it can move up or down depending on how much rain has fallen or how much water is being used from underground.

What is the Water Table?

The water table marks the top of the area where the ground is totally wet, or "saturated," with water. Below this line, all the tiny spaces in the soil and rocks are full of water. Above it, there's still air in those spaces.

How Does Groundwater Form?

Most groundwater comes from precipitation, which is just a fancy word for rain, snow, sleet, or hail. When precipitation falls, some of it runs off into rivers and lakes. But a lot of it soaks into the ground. As it moves deeper, it fills up the empty spaces in the soil and rock layers. Eventually, it reaches a point where all the spaces are full, and that's where the water table begins.

Why is the Water Table Important?

The water table is super important for many reasons:

• Drinking Water: Many towns and farms get their drinking water from wells that tap into the groundwater below the water table.
• Plants and Ecosystems: Plants need water to grow, and some plants get their water directly from the water table if their roots reach deep enough. It also supports wetlands and other natural areas.
• Rivers and Lakes: In many places, the water table feeds rivers and lakes, especially during dry periods. This means groundwater helps keep surface water bodies flowing.

How Does the Water Table Change?

The depth of the water table isn't fixed. It can change a lot!

• Rainfall: After a lot of rain, the water table usually rises because more water is soaking into the ground. During dry spells, it can drop.
• Pumping Wells: If too much water is pumped out of wells, the water table can go down, sometimes causing problems for other wells or for the environment.
• Seasons: The water table often changes with the seasons, being higher in wet seasons and lower in dry ones.

A picture showing how the water table changes with the land above it, and also a "perched" water table which is a small pocket of water above the main one.

Images for kids

• 

  Yield of sugarcane versus depth of the water table in Australia. This shows that sugarcane grows best when the water table is around 0.6 meters deep.

See also

In Spanish: Nivel freático para niños